Keyboard Connection Grid(using matching DB25 connector numbers)
K E Y S									400/800/XL Pin
DEL	>	<	0	9	8		7	BRK	1
ESC	1	2	3	4	5		6		2
RET	=	-	P	O	I		U		3
TAB	Q	W	E	R	T		Y		4
	*	+	;	L	K	J		CTRL	5
CAPS	A	S	D	F	G	H			6
	INV	/	.	,	M	SPC	N		7
	Z	X	C	V	B			SHIFT	8
17	16	15	14	13	12	11	10	9
F U N C T I O N - K E Y S / L E D									400/800 Pin	XL Pin
HELP	RESET		OPTION	SELECT	START		LED	GND
	18		19	20	21			22	22
	23		20	21	22		24	18		18
17										19
In Testing an 800XL extension keyboard with an 800, I had to change switch connections to the following db25 pins:
17	23		22	21	20		24	18		18

800 Connector(viewd from bottom)

Left(1) - - - - - - - - - - - - - - - - - - - - - - - - (17)Right

XL Connector

Back(1) - - - - - - - - - - - - - - - - - - - - - - - - (24)Front

Keyboard Internal Number Grid
K E Y S
X S RRR CCC (location 764)	< 8 to 3 <encoder (CCC)	b0	b1	b2	b3	b4	b5	b6	b7
^^^^^^^^ 8 to 3 encoder (RRR)	b0	L 0	J 1	; 2			K 5	+ 6	* 7
Normally-value is 255, so all bits are high	b1	O 8		P 10	U 11	EOL 12	I 13	- 14	= 15
bits 2-0 from columns	b2	V 16		C 18			B 21	X 22	Z 23
bits 5-3 from rows	b3	4 24		3 26	6 27	ESC 28	5 29	2 30	1 31
	b4	, 32	SPC 33	. 34	N 35		M 37	/ 38	ATARI 39
'S' bit is low when shift is pressed	b5	R 40		E 42	Y 43	TAB 44	J 45	W 46	Q 47
'X' bit is low when ctrl is pressed	b6	9 48		0 50	7 51	BACK 52	8 53	< 54	> 55
	b7	F 56	H 57	D 58		CAPS 60	G 61	S 62	A 63

(NOTE:that with shift and crtl not pressed, letters above are lower case.)

Keyboard Internal Number Grid
K E Y S -- with shift pressed
X S RRR CCC (location 764)	< 8 to 3 <encoder (CCC)	b0	b1	b2	b3	b4	b5	b6	b7
^^^^^^^^ 8 to 3 encoder (RRR)	b0			: 66				\ 70	^ 71
Normally-value is 255, so all bits are high	b1							UND 78	| 79
bits 2-0 from columns	b2
bits 5-3 from rows	b3	$ 88		# 90	& 91		% 93	" 94	! 95
	b4	[ 96		] 98				? 102
'S' bit is low when shift is pressed	b5
'X' bit is low when ctrl is pressed	b6	( 112		) 114	' 115	del 116	@ 117	CLR 118	INS 119
	b7

(NOTE:this table only shows characters not in previous table.)

Cross reference XE to XL pin numbers
XE Key pin numbers
1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24
19	24	18	11	7	8	5	12	13	14	15	3	1	2	4	17	16	6	10	9	20	21	22	23
XL Key pin numbers

It is very easy to use the keycodes in a program. This lets you scan for keypresses while doing something else.
10 NBR=PEEK(764)
20 IF NBR<>255 THEN POKE 764,255
30 REM THIS MAKES SURE THE VALUE DOES NOT INTERFERE LATER. AND THERE IS NO KEYCLICK THAT INTERFERES WITH DLIS.
40 REM YOU CAN USE: 20 OPEN #4,4,0,"K:":GET #4,X:CLOSE #4 ..YOU GET ATASCII, BUT YOU GET A KEYLICK TOO
50 IF NBR=28 THEN GOTO MENU:REM ON ESCAPE
60 IF NBR=12 THEN QUIT:REM ON RETURN
.
90 REM you can even scan the shift/ctrl/option/select/start/help buttons
100 REM DO YOUR ROUTINE HERE
1000 GOTO 10

You might think that you could use an 8X8 array to look up the atascii value for the keycode value, and you can but you use 384 bytes + code, and its slow.

Better to DIM KEYCODE$(256) and put the atascii values in the slot for its keycodes using data statements. And then all you have to do is look it up.(ATASCII=ASC(KEYCODES$(NBR+1))

I prefer to just use the keycodes and save the work of converting to atascii unless I really have to(when I input to a string, I use OPEN to get atascii instead).

Rick D.

(Jan05, revised Oct06)